Apparatus for extracting precious metals from their ores.



No. 820,811. A PATBNTED MAY 15, 1906.

S. T. MUPFLY. APPARATUS FOR EXTRAGTING PRECIOUS METALS FROM THEIR ORES.

APPLICATION FILED AUG.14. 1905.

hire runs I I hat. I

iii" ri SIDNEY T. MUFFLY, OF II-IILADICLPHIA, PENNSYLVANIA, ASSIGNCIR TO PHILADELPHIA OYA NIDIC PROCESS COMPANY, OF WILMINGTON,

DELAWARE, AND PI-IIIn-XIJELPIIIA, PENNSYLVANIA, A CORPORATION OF DELAI'VA ltl l.

fipecification of Letters Patent.

Patented. May 15,1900.

Application filed August 14, 1905. Serial No. 274.120.

To It whom it may concern:

Be it known that I, SIDNEY, T.' MUFFLY, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in an Apparatus for Extract ing Precious Metals from their Ores, of which the following is a specification.

One object of my invention is to provide a novel combination of apparatus by which not only the time required for the treatment of a given body of ore is greatly reduced over what has hitherto been considered necessary in cyanid processes, but the amount ofcyani'l solvent employed is also much less than hitherto. i I It is further desired to provide a combination of apparatus by which it shall be possible while treating ores to save and repeatedly use the cyanid solvent, whose active element, cyanogen, is evolved in the leaching of ores as hydrocyanic-acid gas and at the present timeis ordinarily lost.

I further desire to provide a system by which the labor necessary in connection with the treatment of ores shall be reduced to a minimum and which-shall have such an effi ciency of operation that it shall be commercially possible to treatwith profit lOW QltldG ores running,\for example, about one to two dollars er ton of ore.

Anot ier object of the invention is to provide a system or construction of apparatus in which successive bodies of ore may be continuously treated and by which the cyanogen evolved as hydrocyanic-acid gas is cyclicly restored to the cyanid solvent and reused.

These objects I attain as hereinafter set .forth, reference being had to the accompanying drawings, in which 7 i Figure 1 is a representation, to some extent diagrammatic, of the apparatus comprising my invention; and Fig. 2 is an enlarged vertical section illustrating a portion of the detail construction of the lixiviators.

The: apparatus hereinafter described and ward pressure of compressed air.

crushed ore in a neutralizer. Immediately thereafterI deliver this washed and neutralized ore to the interior of a hermeticallysealed stamp-mortar containing an alkaline cyanid solution exposed to the direct down- This inclosed stamp-mortar formsone end of what may be described as a closed conduit within which the ore is treated, said conduit consisting, beyond said stamp-mortar, of a number of lixiviators connected in series, in which the pulp is successively subjected to fresh bodies of cyanid solution until it is finally delivered as tailings to a device whereby it is removed. The conduit formed by the lixiviators and their connections and the stamp mortar is at all times supplied with air under pressure greater than that of the atmosphere, so that the liquid in this conduit always has direct downward pressure of air upon its surface. The hydrocyanic-acid gas evolved in the process of lixiviation is conducted to a suitable condensing or absorbing chamber, where it is dissolved in a cyanid solution, which is subsequently used in he treatment of further bodies of ore.

. In the above drawings, A re resents an ore, crusher so constructed and a justed that the ore delivered from it will be in pieces not exceeding a quarter to half a cubic inch in volume. Connected to this crusher by a chute a is a neutralizer B, connected, by means of a pipe 0, with a tank C, there being also connected with said neutralizer, preferably 'to the lower part thereof, a filter-tank c, in turn connected with a storage-tank c The neutralizer B preferably consists of an inclosed casing having within it a revoluble drum 6, upon which are lclades or buckets b, there being any desired driving means for turning the drum, in the present instance a worm-wheel b, fixed to the drum-shaft, and e worm b to which power is applied and which meshes with said wheel.

A stamp mortar D, inclosed in an airtight casing, is connected to the neutralizer B by means of a closed conduit 1), which contains a conveying device If, driven in any-desired manner, for the purpose-of transferrin crushed ore from the neutralizer B to 'sui stamp. This conduit is provided with an automatic valve 6, counterweighted, seas to hormally remain closed to cut off communication between the interior of the stampmortar and the neutralizer 1%, the valve, however, being capable of automatically opening when a body of ore is laced upon it.

An air-compressor E, provi with a res ervoir e and a heating-chamber e, 1S connectedso as to supply air to the interior of the stamp-mortar either through a pipe e which is placed to deliver air ad acent to the dies and stamps for the purpose hereinafter mentioned, or through a pipe e which delivers the air into the upper part of the stampmertar casing, or through both of said pipes. A coil of pipe e is usually placed in the chamber e, and this is preferably connected to the exhaust of the stamp-operating engines, so as to supplyheat to the compressed air in said chamber.

Pulp and liquid from the stamp-mortar are conducted through a conduit f, which connects the first of a series-of lixiviatoi's F to the stamp-mortar, and these are so arranged that the last of them delivers the material to an inclosed bucket conveyer G, discharging into tanks, such as are shown at g. Liquid from the lixiviators F may be drawn from the bottom cf the inclosed conveyer-casing G.

through a pipe g into any of a series of filtertanks g The specific construction of the lixiviators used is described and claimed in the applicationfor United States Patent, Serial No. 281,672, filed by me October 6, 1905. i

, Connection is made between the air-heater and each of the lixiviators F through branch pi es connected to a pipe e, in addition to w 'ch each of said lixiviators, as well as the stamp-casing, has connected to it branches from a ipe z in connection with any or all of the tan is h. The last of the lixiviators F is connected by a pipe 7L2 to a condensing or vapor-absorbing chamber H, in which are placed a number of vertically-placed porous partitions formed byendless aprons h, carried upon rollers driven in any desired manner and dipping into a solution delivered from a suitable tank' h These endless aprons alternate withfixed partitions extend"- ing up from the bottom of the chamber H and forming a series of compartments, each of which contains the above-mentioned solution. Liquid from this condensing-chamber may pass through suitable pipes to the tanks h, while the tank h is arranged to deliver into it. The condensing apparatus referred to above and shown in the drawings herewith forms the subject of a separate a plica'tionfor United States Patent, Serial 0. 281,67 3, filed bymefOctober 6, 1905 The 'box I is connected by a pipe '5 with the chamber H and has some form of valve '5 designed to be automatically and periodically opened by a rod i actuated by ratchet mechanism actuated from the driving means of the lixivators F. In the present instance these liidviators are of the same construction as the neutraliher B, and they are all driven by a common shaft through belts which drive wormcaring operative upon the main shaftof the ucket or paddle carrying drum within the lixivator-casing.

Under operating conditions ore s delivered from the crusher A in a comminuted state to theneutralizer B, where it is intimately mixed with a neutralizing solution supplied from the tank (J, which solution preferably consists of an alkaline hydrate, such as sodium or potassium hydrate. is designed to neutralize any acid salts which may be present in the ore due to the oxidation of sulfide or as a result of the action of water on decaying vegetable matter The revolution of the drum 1) of the neutralizer B deposits the neutralized and washed ore upon the conveyer 6 which delivers it to the counterweighted valve b and this automatically operates to discharge said ore into the stamp-mortar D. The interior of the stamp-mortar is filled with a weak cyanid solution, which may vary from .1 or less to .5 of one per cent, as the nature of an ore may require, this solution being delivered from the'tank h. Air is also supplied from the compressor E through pipe e to the inte-' rior of the stamp-mortar, and such air is 1pieferably kept at a temperature of or 'gher, by means of the heating-coil c and is at a pressure of ten pounds or greater to the square inch.

If the ore under treatment is of a slaty or argillaceous nature, itmay be also advisable to deliver air under pressure through the pipe e in order to prevent the pulp or ore clo ging the stamp. Screens of any desired mes are rovided at (1 so that the pulp delivered cm the stamp is of a certain fineness, and said pulp with a portion of the weak cyanid solution flows to the various lixivators F,

"where it is brought into intimate. contact with a succession of fresh-bodies'of cyanid solution which are at all times exposed to an air-pressure-greater than that of the atmos phere, cting directly downwardly upon their S111 aces and which is delivered through pipes e.

I have found that the direct downward pressure of air greater than that of the atmosphere, exerted upon the surface of the cyanid solution, very materially hastens the solvent action of the cyanid solution,and by this means I am enabled to accomplish one of the im ortant objects of my inventionnamely, t e shortening of the time necessary to treat a iven body of ore I have a so found that by treating the ore within a closedcpntainer and under air-pressure acting directly downward upon the surface of the solution said solution is .caused to extract a much larger percentage of metal from the orein some cases practically all of This solution aaasii itwhere hitherto it has been possible to extract by the cyanid process but a comparatively small amount of the'precious metal, depending upon the complex or free nature of the ore.

It will be understood that the chemical reactions occurring in the treatment of body of ore with a solution of a cyanid necessarily result in the freeing of relatively large amounts of hydrocyanic gas, and instead of allowing this gas to escape and go to waste as has hitherto been the custom, I cause it, with air under pressure, to pass out of the last of the lixivlators F through the pipe h and deliver it to a condensing-chamber H. In this latter a solution, preferably containing a double cyanid, such as cyanid of potassium and bromin, absorbs the hydrocyanic-acid gas, by reason of the fact that this latter is soluble in water and because the presence of the bromin compound materially aids and accelerates such action, and I cause such solution to be delivered from time to time or continuously, as desired, to the tanks h, from whence it is permitted to flow to the stamp-mortar and the various l xiviators, where it is used again to treat ores.

By causing acid as to pass through a rons of burlap saturated by the above-noted solution the latter very completely and quickly absorbs it, and in order to prevent the passa e of any compounds or vapors of base meta ic salts frequently carried with the hydrocyanic-acid gas andthe compressed air I deliver into the condensing-chamber a solu tion of ammonic hydrate from the vessel k thereby forming hydrates with any base metallic compounds so entering and causing these to remain in. the chamber H.

- The compressed air is periodically allowed to escape from the chamber H through the box I, the valve i on this box being intermittently opened by action of the ratchet mechanism upon the rod if.

'From the last lixiviator F the ore-pulp or tailings, from which the gold and silver has been dissolved, pass into inclosed conveyer G and are carried by buckets to covered tanks g, containing Wash-Water, to recover asmall amount of the metals remaining in cyanid moisture. After removing the Wash-water for, further use the tailings are then discharged from tanks ,1 to a waste-dump, or, if containing valuable byproducts, to some other desired place by means of the sand-pump.

The cyanid solution containing the precious metals is drained from conveyer G through pipe Mintotanks ghwhere it is filtered, and/flows to storage-tanks for treatment in a series of electrolytic or other appa- 'ratus (not shown) for precipitation of the gold and silver, the solution thereafter bein raised by a ump (not shown) to tanks an strengthene with fresh cyanid solvent com poun for further use in treating ores.

veyer It will be understood by those skilled in the art that by providing means for regencr ating and reusing the cyanogen evolved as hydrocyanic-acid gas during the operation of my system I am enabled to greatly reduce the cost of operation of the same, since the cyanid solvent constitutes one of the expensive items in the operation thereof. Further, by the use of compressed air during the stamping and chemical action on the orepulp, not onlyiis the time of treatment of the ore greatly lessened, but a very much greater proportion of the precious metals contained therein is caused to be dissolved by the cyanid than has hitherto been considered possible.

I claim- 1. A system for treating ores to extract the precious metals therein contained, which con-.

sists of the combination of anore-neutralizing device, an inclosed stamp-mortar, and a closed conduit connecting said device with the stamp, substantially as described.

2. A system for treating ores to extract the precious metals therein contained, which consists of the combination of an ore-neutralizing device, an inclosed stamp-mortar, a closed conduit connecting said device with said stamp-mortar, and an automatic valve in said conduit,'substantially as described.

3. A system for treating ores to extract the precious metals therein containedavhich consists of the combination of an ore-neutralizing device, an inclosed stamp-mortar, and a closed conduit connecting said device with the stamp-mortar, said conduit having a conlaced to receive material from said neutralizing device, and an automatic valve placed to receive material from the conveyor,

substantially as described.-

4. A system for treating ores to extract the precious metals therein contained, which con.-

sists of the combination of an ore-neutralizing device, a stamp-mortar having an air tight casing, and a source of air-supply connected to deliver air to said. stamp-mortar casing, substantially as described.

J5. A system for treating ore to extract the precious metals therein contained, which consists of the combination of an ore-neutralizing device, a stamp-mortar having an airtight casin and a source of air-supply connected to eliver gairto the said stamp-mortarand casing, said mortar having within it means for discharging the air both-above the surface ofa body of ii uid in it and also un-' der the surface ol said iq'uid adjacent to the stamps and dies, substantially as described.

6. A system for treating ores to extract the precious metals therein contained, the same consisting of an inclosed conduit, an ore-neutralizing device discharging into one end of said conduit, and a stamp-mortar and lixivi ating means, all operative in. the conduit, substantially as described.

7. A system for treating ores to extract the precious metals therein contained, the same consisting of (an inclosed conduit, a stampmortar, lixiviating means connected to receive material from he stamp'mortar, and a source of air-supply connected to cause direct downward pressure upon the bodies of liquid in said conduit, substantially as described.

8. .A system for treating ores to extract the precious metals therein contained, which includes a crusher, a neutralizing device, a stamp-mortar, a lixiviating device, means connecting said parts to form a continuous inclosed passage for ore, and a compressor connected to said passage to maintain the air in the stamp-mortar and in the lixiviating device under a pressure above the normal, substantially as described.

9. A system for treating ores to extract theprecious metals therein contained which in cludes a stamp-mortar having an inclosed casing, a series of lixiviators connected to the stamp-mortar, each lixiviator consisting of a casing having a drum provided with buckets and driving meanaand means for supplying cyanid solution and air under pressure to the stamp-mortar and to the lixiviator-casing's, substantially as described.

10. In a system for treating ores to extract the precious metals therein contained, the combination of an inclosed stamp-mortar, a series of inclosed lixiviators connected to receive material frointhe stamp, a vessel for receiving liquid from the lixiviators, means for removing the tailings, and an absorbing apparatus connected to said lixiviators for receiving the hydrocyanic-acid gas evolved in said lixiviators, substantially as described.

11. A system for treating ores to extract the precious metals therein contained which includes an inclosed stamp-mortar, a series-0t inclosed lixiviators connected to receive material from the stamp, a series of receivingtanks, an absorbing device and a eonveyerf all connected to the lixiviators, said absorbing devices consisting of a chamber having connected to it a source of supply for solution capable of absorbing hydrocyanic-acid fumes, substantially as described.

12. A svstem for the treatment of ores of precious metals including a series of lixiviators and an absorbing-chamber connected thereto, said chamber having series of partitions forming a tortuous passage therethrough and being provided with means whereby a solvent solution may ,be sup lied o said partitions, substantially as described.

13. A system for the treatment of the ores pf precious metals including a seriesof lixiviators and a gas-absorbing chamber conpected thereto, said chamber having series of partitions forming a tortuous passage therethrough, one series of said partitions being formed of fabric aprons having me ans whereby they are made to dip into a body of liquid in the bottom of the chamber, and means whereby their surfaces are supplied with relatively thin films of liquid.

14. In a system for the treatment of the ores of'precious metals, the combination of a series of lixiviators, a source of compressed air connected thereto, means tor receiving liquid and pulp after said materials have passed through said lixiviators an absorbingchamber for receiving the hydrocyanic-acid gas evolved, and means for permitting the escape of the compressed air after it has passed through the absorbing-chamber, substantially as described. Y

15. In a system for the treatment of the ores of precious metals, the combination of'a series of lixiviators, a source of compressed air, means for receiving li uid and pulp after said materials have passe through said lixiviators, with an absorbing-chamberconnected to the lixiviators for receiving the hydrocyanic-acid gas evolved, and positivelyacting means for periodically permitting the es cape of the compressed air after it has passed through the absorbingchamber, substantially as described.

16. A chamber for absorbing gas consisting of a container having partitions extending upwardly from its bottom, pairs of rollers between certain of the partitions, and fabric aprons extending vertically between each pair of rollers and entering bodies of liquid in the lower part of the chamber, substantially as described.

17. A. chamber for'absorbing gas, consisting of a container having partitions extending upwardly from its bottom, pairs of rollers between certain of the artitions, fabric aprons extending vertical y between each pair of rollers and entering bodies of liquid in the lower part of the chamber, and means for turning certain of the rollers to cause movement of the aprons, substantially as described.

v 18. A system including the combination of an inclosed stamp-mortar and a series of inclosed lixiviators, with a chamber connected thereto for absorbing hydrocyanic acid gas evolved, a container' tor cyanid solution, and a container for alkaline-hydrate solution, both connected to said absorbing-chamber, substantially as described.

19. In a system for the treatment of the ores of precious metals, the combination of a stamp-mortar, capable of .holdin liquid, a casing therefor capable of hol ing compressed air, a source of compressed air, and means for connecting said source of air with the casing, said connecting'means including a pipe connecting with the top of the stampmortar and a second pipe laced to dischar e adjacent to the stamps an dies, substantial y as described.

20. In a system for treatment of fine ore sand, clays, concentrates and mail-tailings containing precious metals, which consists of the combination of an acid-neutralizer with a chute at the back for the material to enter, a

closed conduit at the front having a conveyer vwith an automatic valve laced to discharge the material to a series of ixiviators connecting with-a gas-absorbing chamber having an automatic valve, connection with an ore-conro vever, with a sand-pump, with a solutionpump, with solution-tanks, with an air-compressor, and with an electrolytic or other gold and silver precipitating apparatus, substantially as described.

21. In a system for the treatment of ores containing precious metals, which consists of the combinations of an ore-crusher connected by a chute with an acid-neutralizer at the back for the broken ore to enter, with a closed conduit at the front having a conveyer with an automatic yalve to discharge the broken ore into a fine crushing or pulverzing mill having pipe attachments for supplying air under pressure, a pipe for supplylng solvent solution, connecting by an inclosed conduit with a series of lixiviators having air-receivers, with pi e connections with an aircompressor, Wit pipe connections with solution-tanks, with a gas-absorbing chamber, with an ore-conveyer, with a solution-pump, with a sand-pom and with an electrolytic or other gold and si ver preci itating apparatus, substantially as described? In testimony whereof I have signed my name to this specification in the presence of" two subscribing witnesses.

SIDNEY T..MUFFLY.

Witnesses:

WILLIAM E. BRADLEY, Jos. H. KLEIN. 

